In general, washing machines are designed to remove foreign substances absorbed in the laundry, while water supplied to the laundry is mixed and rotated or revolved.
There are various types of washing machines, including pulsator type washing machines that wash laundry using water streams generated by a pulsator in the tub. In the pulsator type washing machines, washing and spin-drying operations are performed in the water tank, and a suspension is disposed outside the water tank to prevent noise and movement of the tub due to excessive vibrations during the wash cycle or spin cycle.
However, depending on the amount of laundry placed in the water tank, the weight of the water tank may increase significantly due to the absorbed water the in laundry during the wash cycle. As a result, the difference in the entire weight depends on the amount of laundry in the tub and/or drum. Therefore, the entire weight of the water tank is proportional to the amount of laundry being washed.
Accordingly, vibrations, shock, and noise from the water tank during the wash cycle or the spin cycle may be absorbed and/or reduced by supporting the water tank at four points with a suspension. The suspension includes a compression spring that is designed in accordance with specifications that consider low-load conditions, but that is based on of the maximum load of the water tank.
However, when a small amount of laundry is washed, micro-vibrations may be generated due to the high elasticity of the compression spring. In contrast, when there is a relatively large amount of laundry, the water tank may become unbalanced and the suspension may fail to sufficiently absorb vibrations.